DESCRIPTION: The investigators propose the development of a new and extensive gene database directed at questions relating to obesity. This database can be seen as complimenting similar databases already being developed for African-American and Latin groups in other parts of the country as well as the Ottawa family study in Canada. The investigators propose analyzing genetic variance at a variety of genomic sites as well as general genomic screen with respect to potential correlation with six specific phenotypic variables associated with obesity: Total body fat mass by dual energy x-ray absorptiometry, visceral fat size by CT, insulin sensitivity by minimal model, LDL density size distribution by gradient gel electrophoresis, left ventricular hypertrophy by echo, and acute insulin response to IV glucose bolus. The rationale for the selection of these variables relates to the development of adverse effects associated with obesity particularly, more so than to obesity as a general phenomenon. The sample group will consist of 880 individuals drawn from a database consisting of 1,465 individuals belonging to 304 families and specifically having 326 concordant and 596 discordant sib-pairs. Data, including DNA samples and baseline anthropometric measures have been already acquired on this database. The investigators propose measurement of the specific variables indicated above and correlation of those with genomic variance through either sib-pair linkage analysis or the more recently proposed variance components linkage analysis from the San Antonio group.